Moderate Vulnerability in Python 3.12: Excessive Read Buffering DoS
Summary
ALSA-2026:2419: Moderate: python3.12 security update. Affects python3.12 versions < 3.12.12-2.el8_10. Fixed in 3.12.12-2.el8_10. How to fix ↓
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Background
Python 3.12 is an interpreted, interactive, object-oriented programming language that supports modules, classes, exceptions, and dynamic data types. It is widely used for various applications, including web development, data analysis, artificial intelligence, and more. The language provides interfaces to numerous system calls and libraries, making it versatile and powerful. However, like any software, it is susceptible to vulnerabilities that can affect its performance and security.
Vulnerability Detail
The vulnerability identified as CVE-2025-13836 pertains to an excessive read buffering Denial of Service (DoS) issue in the http.client module of Python 3.12. This flaw allows an attacker to exploit the excessive buffering mechanism, potentially leading to resource exhaustion and service unavailability. The vulnerability arises from improper handling of HTTP client requests, which can be manipulated to consume excessive memory or processing resources, thereby impacting the application's performance and availability.
How To Fix
Minimum fixed version
3.12.12-2.el8_10
This is the first release that contains the fix.
sudo dnf update python3.12Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, it is advisable to limit the maximum size of HTTP requests processed by the application. This can be achieved by implementing request size validation in your application code to prevent excessive resource consumption.
Conclusion
The vulnerability CVE-2025-13836 in Python 3.12 poses a moderate risk due to its potential to cause Denial of Service attacks through excessive read buffering. It is crucial to update to the latest patched version to ensure the security and stability of applications using this version of Python. Additionally, utilizing tools like Vulert can help monitor and manage vulnerabilities effectively.
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FAQ
CVE-2025-13836 is a vulnerability in Python 3.12 that allows for excessive read buffering, leading to potential Denial of Service (DoS) attacks.
You can use Vulert, which monitors and alerts for open-source vulnerabilities in real-time. Simply upload your manifest file like package-lock.json to check for vulnerabilities.
If exploited, this vulnerability can lead to resource exhaustion, causing the application to become unresponsive or crash, affecting user experience and service availability.
Yes, a patch is available in the form of an updated version of Python 3.12 (3.12.12-2.el8_10) that addresses this vulnerability.
If immediate updating is not possible, implement request size validation as a temporary workaround to mitigate the risk of exploitation.
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